Violence between Hamas gunmen and Fatah-allied guards broke out at the Rafah border crossing soon after Israel announced it was to be closed.

More than two dozen people were hurt.

Haniyeh cut short a trip abroad to return to Gaza in a bid to quell the infighting between Hamas and Fatah. The violence showed no signs of slowing Thursday, as pro-Fatah Palestinian officers arrested a Hamas-linked militant in the killing of three small children of a Fatah security chief. The militant's allies retaliated by kidnapping a security officer.

Thursday's gunbattle erupted after Hamas militants, angry that Israel was preventing Haniyeh from returning to Gaza, stormed the border terminal.

The pro-Fatah Presidential Guard, responsible for securing the area, opened fire, setting off a gunfight. Terrified travelers ran for cover, some carrying their luggage. Crying women and children hid behind walls and nearby taxis outside, while the European monitors whom police the crossing fled. Two Hamas militants were wounded in the gunfight.

The Hamas militants, chanting "God is Great, let's liberate this place" took over the arrival hall, and the border guards escorted the European monitors to safety. In the chaos of the attack, two loud explosions rocked the border area, and security officials said militants had blown a hole in the border fence about one kilometer (half a mile) from the terminal.

Late Thursday, hundreds of Hamas forces were patrolling the border area as Presidential Guards nervously looked on. But as Egyptian officials negotiated with the Europeans to reopen the border, impatient Hamas gunmen angry over the delays re-entered the area and began firing across the border. Egyptian officials said troops fired in the air to keep Palestinians from crossing.

The rampage destroyed furniture and computer equipment inside the terminal and plunged the area into darkness. Hospital officials said 27 people were wounded, two seriously.

Under a U.S.-brokered agreement, the border can only operate in the presence of European monitors. Thursday's unrest was likely to strain the deal, which turned over control of the crossing to the Palestinians last year after four decades of Israeli control.

Israeli Defense Minister Amir Peretz, working with the EU monitors, had ordered the border closed to prevent Haniyeh from bringing in tens of millions of dollars he raised during a tour of Muslim countries, security officials said.

A senior Israeli security official said they were not trying to block Haniyeh's entry, only to keep out the money. The official said Israel had information the money would be used to strengthen Hamas or fund terror attacks, but he declined to provide further details. The official spoke on condition of anonymity because he was not authorized to discuss the matter with the press.

A Palestinian official said Haniyeh was carrying $35 million he raised during his recent trip, which included stops in Syria and Iran.

European officials said there had been an agreement for the money to be deposited into an Egyptian bank account, but it was unclear if the money had been deposited.

Haniyeh departed Gaza on Nov. 28 for what was supposed to be a month-long trip to the Muslim world, with a main goal to raise money for his government.

The Palestinian Authority has been crippled by international economic sanctions that have left it unable to pay full salaries to its 165,000 workers. Israel and Western donor nations cut off hundreds of millions of dollars for the government after Hamas won legislative elections early this year, demanding the terrorist group renounce violence and recognize Israel.

Hamas has rejected the demands and instead turned to Iran and other Muslim countries for help. Hamas officials have physically delivered more than $50 million to Gaza this year — far short of the government's needs.

Since Haniyeh left, the situation in Gaza has only worsened.

Palestinian President Mahmoud Abbas, of Fatah, has been trying to persuade Hamas to join his more moderate party in a coalition government in hopes of lifting the sanctions. But talks between the sides broke down late last month.

Tensions further heightened after Abbas threatened to call new elections, drawing charges from Hamas that he is plotting a coup. Abbas is scheduled to deliver a major speech outlining his plan on Saturday.

The latest violence broke out early this week when unknown gunmen riddled the car of a Fatah security officer, killing his three young sons. Fatah accused Hamas of carrying out the shooting — a charge Hamas denied. The officer, apparently the target of the attack, was not in the car at the time.

On Wednesday, gunmen in the southern Gaza Strip ambushed a prominent Hamas commander and killed him in an execution-style slaying outside a courthouse. Hamas accused a Fatah "death squad" of being behind the killing.